An exhaust gas recirculation system may be used to reduce the generation of undesirable pollutant gases during the operation of internal combustion engines. Exhaust gas recirculation systems generally recirculate exhaust gas generated during the combustion process into the intake air supply of the internal combustion engine. The exhaust gas introduced into the engine cylinders displaces a volume of the intake air supply that would otherwise be available for oxygen. Reduced oxygen concentrations lower the maximum combustion temperatures within the cylinders and slow the chemical reactions of the combustion process, which decreases the formation of oxides of nitrogen (NOx).
The intake air supply is often compressed through a turbocharger and then supplied to an intake manifold. Exhaust gas is introduced into the intake air supply between the turbocharger and the intake manifold. Structures for mixing the exhaust gas with the intake air supply may take many different forms. The flow characteristics of the intake air supply and the exhaust gas affect the degree to which the air and the exhaust gas mix. Consistent mixing of the air and exhaust gas typically results in improved engine performance.
U.S. Pat. No. 7,624,722 discloses a system for recirculating exhaust gas within an internal combustion engine. An intake air conduit receives an intake air stream and an exhaust gas stream and blends or mixes the two streams together. A volute redirects the exhaust gas stream into the intake air stream to achieve the desired mixing.
The foregoing background discussion is intended solely to aid the reader. It is not intended to limit the innovations described herein nor to limit or expand the prior art discussed. Thus the foregoing discussion should not be taken to indicate that any particular element of a prior system is unsuitable for use with the innovations described herein, nor is it intended to indicate any element, including solving the motivating problem, to be essential in implementing the innovations described herein. The implementations and application of the innovations described herein are defined by the appended claims.